The current status of active surveillance for prostate cancer.

The occurrence of low-risk, localized prostate cancer (PCa) has increased in the prostate-specific antigen era. A significant amount of low-risk PCas progress slowly and may not impact patient survival. Thus, these patients may be subjected to unnecessary interventions that result in physical and psychological complications. The active surveillance (AS) protocol has been used over the few past decades. It was designed so that patients with low-risk PCa can be monitored for a period of time, during which they are free from complication of interventions, and can be treated with curative intention on evidence of disease progression. Institutions have developed different selection criteria and follow-up schedules for suitable patients with PCa. Recently, long-term data have emerged suggesting that AS is a reasonable option for appropriately selected patients with low-risk PCa who have a life expectancy of < 10 years. Subsequently, the AS protocol has been recognized by various guidelines as part of the treatment strategy for PCa. However, the challenges that remain for AS are the risk of under-staging of PCa and the low uptake and high attrition rate of AS, and questions remain regarding its long-term efficacy. Recent advances in AS for PCa, such as better imaging modality, combining AS with limited local therapy, as well as the role of AS in association with chemoprevention, are discussed.